Hello

Im trying to better understand blockchain and I cant seem to find the answer for the questions below:

In a blockchain, you would typically store only hashes and no real content such as names or any other text elements, right ?

I understand the blockchain is not hosted with a classical webhosting provider. But doe this mean that the chain is stored on every single computer or server connected to the blockchain and is being synced ? (or only computer that has some kind of software installed which connect to the blockchain)

What if the blockchain is 50 GB large ? Does this mean every single person will store this 50 GB large blockchain on their PC or smartphone ?

How does an application connect to a blockchain, by a port, URL, ID ?

Thx for your help

Mateo